2016 Sender Score Benchmark

If you don’t know your Sender Score, look it up here and then come back and follow along.

Introduction

In the quest to land in the inbox, sender reputation is one of the most influential factors that determines if and where email is delivered. Mailbox providers use sender reputation as a way to judge whether a sender is legitimate and wanted by their mailbox users, or whether they are sending spam and should be blocked from the inbox.

Marketers who are aiming for the inbox use Return Path’s Sender Score to discover and track their sender reputation and learn how their messages appear to mailbox providers. Sender Score uses similar data points and reputation formulas that mailbox providers use to give a nearly accurate representation to how mailbox providers see your email. Similar to a credit score, Sender Score is an evaluation of your reputation as a sender and of the quality of your messages and your email program. Each marketer’s Sender Score is a number between 0 and 100.

There are many different elements that combine to determine your sender score—list hygiene, complaints, and spam traps to name a few. For description of all the variables that go into your Sender Score, read this in-depth overview: All About Your Sender Score.

This report showcases the state of email reputation, analyzing:

Where all attempted messages are coming from and how much of that is getting delivered

How the reputation landscape has changed year over year

How the top mailbox providers are choosing to place messages based on their sender’s reputation

The State of the Email Ecosystem

Spam is everywhere but the inbox.

Mailbox providers and their filters are constantly evolving, learning to distinguish the good from the bad—and the past year was no exception.

In 2015, out of more than four trillion messages sent, more than half (56 percent) were blocked based on poor sender reputation. Senders with a score below 70 suffered the most with an average delivered rate of nine percent and accounted for more than half of the messages attempted.

Senders scoring above 71 saw an average delivered rate of 93 percent, and represented 90 precent of all email delivered in 2015.

The Top 10 Percent

Those with a Sender Score between 91 and 100 saw fewer messages blocked from the inbox. However, at the top, a single point holds more weight. Those scoring between 91 and 94 saw eight percent of their email diverted from the inbox, whereas for those with a score between 99 and 100 had only two percent blocked.

Year-Over-Year Delivered Rate

Our research revealed less spam in the overall email mix during 2015 than there has been in the past. In 2014, 71 percent of messages attempted came from senders with a score below 71. But this rate dropped to 52 percent in 2015 with senders scoring 71 or above making up the other 48 percent of messages attempted.

Change in Metrics and Sender Score

Complaint rate has a strong effect on Sender Score. A high complaint rate signals to mailbox providers that the sender’s content is unwelcome and should be sent to spam. In 2015, senders with poor reputation were found to have an average complaint rate of 2.38 percent, whereas those with a Sender Score above 70 had an average complaint rate of 0.47 percent.

Those with list hygiene issues will also notice a drop in their Sender Score. The effect of spam traps is most noticeable at the lower end of the spectrum; however, even at top, traps on your list will prompt mailbox providers to view your email as spam.

Inbox Placement by Sender Score

Sender Score is directly related to inbox placement rate. In fact—similar to the delivered rate discussed above—the higher the Sender Score, the better your deliverability. Inbox placement rate starts at around four percent for the senders with the lowest Sender Score, slowly increasing to about 45 percent for senders with a Sender Score of between 50 and 80. Inbox placement rate increases dramatically to an average of about 80 percent for senders with a Sender Score between 80 and 100.

While 80 percent inbox placement rate seems like a steep drop from the delivered rates in the 90s we reported earlier in this report, this difference is not the fault of your reputation. Instead, it relates to your subscriber engagement. Sender reputation has a huge impact on your ability to get into the inbox. Those with a low score aren’t even considered by mailbox providers. But a high Sender Score can only take you so far (about 80 percent of the way there).

To ensure your messages hit the inbox, you need to also be conscious of how your subscribers are interacting with your email. Not sure what metrics to track? Check out our previous study, Hidden Metrics of Email Deliverability, to find out which engagement metrics mailbox providers factor into their filtering decisions.

Using Sender Score for Insights at the Top Four Mailbox Providers

Our research also looked at how senders with different Sender Scores get filtered at the major mailbox providers. AOL and Yahoo’s reputation filters strongly correlate with Sender Score as messages are delivered at or above the average. Gmail mailboxes, however, are challenging for all senders with a score below 80; those above 80 seeing a sharp increase in their inbox placement.

Each mailbox provider has its own formula that scores incoming mail to determine whether to deliver it or filter it. The formulas generally contain the same elements (unknown users, spam traps, complaints, etc.), however, each mailbox provider assigns a different weight to these variables. In addition to your overall reputation, some mailbox providers—specifically, Gmail, Microsoft, Yahoo, and AOL—also incorporate individual level engagement (ignores and deleting unread) into their filtering decisions.

In the chart above, we can see that IP-level reputation filtering is still important in their spam filtering algorithms as IP addresses with a Sender Score below 80 receive little to no consideration for inbox placement. Marketers who ignore complaints and hang on to spam traps and unknown users on their list will come to find their email banned from the inbox as those metrics begin to impact their sender reputation. But at these four mailbox providers, a high Sender Score doesn’t necessarily correlate to higher inbox placement rates. This is due to engagement filtering which isn’t currently a measurement in Sender Score.

Conclusion: How to Raise Your Score

There are many elements that make up your sender reputation. Below are the most critical factors and resources to help you improve each, and ultimately raising your score and your deliverability.

Unknown users/Hard bounces: As soon as you receive a 5xx code after sending to an email, remove that email from your list. To learn about the different types of bounces and how to process them, read the Email Marketer’s Guide to Bounce Processing.

Methodology

To conduct this report Return Path analyzed over 4 trillion messages sent during 2015 from IP addresses whose Sender Score was calculated, and whose subscriber engagement and inbox placement data were available for analysis. In addition to Sender Score data, this report used data from the Return Path Reputation Network to track inbox placement rates across mailbox providers. Data used for this report were aggregated and anonymous, and not limited to Return Path clients. Service available at senderscore.org.